Abstract: A method for starting a wind turbine with hinged wind turbine blades, the wind turbine further comprising an adjustable biasing mechanism arranged to apply an adjustable biasing force to each wind turbine blade which biases the wind turbine blade towards a position defining a minimum pivot angle. The biasing mechanism is adjusted to apply a predefined biasing force to each wind turbine blade, and the pivot angle of each wind turbine blade is monitored. The wind turbine is started in the case that the pivot angle of at least one wind turbine blade exceeds a predefined pivot angle threshold.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a chord which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the chord at the hinge position is larger than or equal to the chord at the inner tip end (5a) and larger than the chord at the outer tip end (5b).

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) mounted on the tower (2) via a yaw system, a hub (4) mounted rotatably on the nacelle (3), the hub (4) comprising a blade carrying structure (5), and one or more wind turbine blades (6) connected to the blade carrying structure (5) via a hinge (7) is disclosed. Each wind turbine blade (6) is thereby arranged to perform pivot movements relative to the blade carrying structure (5) between a minimum pivot angle and a maximum pivot angle. The blade carrying structure (5) is provided with one or more elements (8) configured to improve aerodynamic properties of a surface of the blade carrying structure (5) by increasing a lift and/or decreasing a drag of the blade carrying structure. The increase in lift and/or decrease in drag varies as a function of angle of attack (AOA) between the blade carrying structure (5) and the incoming wind.

Abstract: A horizontal axis wind turbine (1) with a wind turbine blade (5) is disclosed, the wind turbine blade (5) comprising a hinge (6) arranged to connect the wind turbine blade (5) to a blade carrying structure (4) of the wind turbine (1), at a non-zero distance from an inner tip (5a) and at a non-zero distance from an outer tip (5b) of the wind turbine blade (5). An outer blade part (7) is arranged between the hinge region and the outer tip (5b), and an inner blade part (8) is arranged between the hinge region and the inner tip (5a). The outer blade part (7) extends from the hinge region along a first direction and the inner blade part (8) extends from the hinge region along a second direction, and the first direction and the second direction form an angle, ?, there between, where 0°<?<90°.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade canying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) is connected to the blade canying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The wind turbine (1) further comprises a stop mechanism arranged to move the wind turbine blades (5) to a safe pivot angle in the case of an emergency, the stop mechanism comprising a release mechanism (8, 12, 14) and at least one wire (9, 10) interconnecting the release mechanism (8, 12, 14) and each of the wind turbine blades (5).

Abstract: The present invention relates to a method for operating a wind turbine (1). The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The method comprises the steps of detecting an airborne object entering a predefined zone around the wind turbine (1), comparing a current tip height (H) of the wind turbine (1) to a maximum tip height value, the maximum tip height value representing a maximum allowable tip height under currently prevailing conditions.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected to thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a thickness which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle.

Abstract: A wind turbine blade (6) having a span-wise direction between an inner tip region (6a) and an outer tip region (6b), and a chord-wise direction (AA) perpendicular to the span-wise direction is disclosed. The wind turbine blade (6) comprises a hinge (7), an outer blade part (8) and an inner blade part (9). The hinge (7) is arranged to connect the wind turbine blade (6) to a blade carrying structure (5) of a wind turbine (1). The hinge (7) is arranged at a distance from the inner tip region (6a) and at a distance from the outer tip region (6b). The outer blade part (8) is arranged between the hinge (7) and the outer tip region (6b) and the inner blade part (9) is arranged between the hinge (7) and the inner tip region (6a). The inner blade part (9) comprises at least two inner blade portions (20) each having a profile and wherein the inner blade portions (20) are arranged such that the profiles are spaced from each other in the chord-wise direction (AA).

Abstract: A horizontal axis wind turbine (1) with a wind turbine blade (5) is disclosed, the wind turbine blade (5) comprising a hinge (6) arranged to connect the wind turbine blade (5) to a blade carrying structure (4) of the wind turbine (1), at a non-zero distance from an inner tip (5a) and at a non-zero distance from an outer tip (5b) of the wind turbine blade (5). An outer blade part (7) is arranged between the hinge region and the outer tip (5b), and an inner blade part (8) is arranged between the hinge region and the inner tip (5a). The outer blade part (7) extends from the hinge region along a first direction and the inner blade part (8) extends from the hinge region along a second direction, and the first direction and the second direction form an angle, ?, there between, where 0°<?<90°.

Abstract: A method for controlling a wind turbine (1) is disclosed. The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. A maximum noise level value representing a maximum allowable noise to be generated by the wind turbine (1) is received. An optimal pair of tip speed for the wind turbine (1) and rotational speed of the wind turbine (1) is derived, based on the received maximum noise level value. The pivot angle of the wind turbine blades (5) is then adjusted to a pivot angle which results in the derived optimal pair of tip speed and rotational speed.

Abstract: The present invention relates to a method for operating a wind turbine (1). The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The method comprises the steps of detecting an airborne object entering a predefined zone around the wind turbine (1), comparing a current tip height (H) of the wind turbine (1) to a maximum tip height value, the maximum tip height value representing a maximum allowable tip height under currently prevailing conditions.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) mounted on the tower (2) via a yaw system, a hub (4) mounted rotatably on the nacelle (3), the hub (4) comprising a blade carrying structure (5), and one or more wind turbine blades (6) connected to the blade carrying structure (5) via a hinge (7) is disclosed. Each wind turbine blade (6) is thereby arranged to perform pivot movements relative to the blade carrying structure (5) between a minimum pivot angle and a maximum pivot angle. The blade carrying structure (5) is provided with one or more elements (8) configured to improve aerodynamic properties of a surface of the blade carrying structure (5) by increasing a lift and/or decreasing a drag of the blade carrying structure. The increase in lift and/or decrease in drag varies as a function of angle of attack (AOA) between the blade carrying structure (5) and the incoming wind.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade canying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) is connected to the blade canying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The wind turbine (1) further comprises a stop mechanism arranged to move the wind turbine blades (5) to a safe pivot angle in the case of an emergency, the stop mechanism comprising a release mechanism (8, 12, 14) and at least one wire (9, 10) interconnecting the release mechanism (8, 12, 14) and each of the wind turbine blades (5).

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected to thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a thickness which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle.

Abstract: A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a chord which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the chord at the hinge position is larger than or equal to the chord at the inner tip end (5a) and larger than the chord at the outer tip end (5b).

Abstract: A multirotor wind turbine (1) comprising a tower structure (2) and at least one load carrying structure (3, 4), each load carrying structure (3, 4) being arranged for carrying two or more energy generating units (5, 7) comprising a rotor (6, 8). At least two of the rotors are upwind or downwind rotors (6), the energy generating units (5) comprising upwind or downwind rotors (6) being arranged with their centres of gravity at a first distance behind the tower structure (2) along a direction of the incoming wind, substantially at the same vertical level, and at opposite sides of the tower structure (2) at substantially the same second distance to the tower structure (2) along a direction substantially perpendicular to the direction of the incoming wind. The multirotor wind turbine (1) is self-yawing, even under turbulent wind conditions.

Abstract: A multirotor wind turbine (1) comprising a tower structure (2) and at least one load carrying structure (3, 4), each load carrying structure (3, 4) being arranged for carrying two or more energy generating units (5, 7) comprising a rotor (6, 8). At least two of the rotors are upwind or downwind rotors (6), the energy generating units (5) comprising upwind or downwind rotors (6) being arranged with their centres of gravity at a first distance behind the tower structure (2) along a direction of the incoming wind, substantially at the same vertical level, and at opposite sides of the tower structure (2) at substantially the same second distance to the tower structure (2) along a direction substantially perpendicular to the direction of the incoming wind. The multirotor wind turbine (1) is self-yawing, even under turbulent wind conditions.

Abstract: A deformable trailing edge section (3) of a wind turbine blade (1), at least part of said section (3) being formed in a deformable material. The blade section (3) comprises one or more cavities (5) being in connection with or connectable to a fluid source in a way that allows fluid to stream from the fluid source to the cavity or cavities (5), so that the shape of the deformable trailing edge section (3) and thereby the camber of the blade cross-section (3) is changeable by the pressure of fluid in the cavity or cavities (5) with insignificant changes of the thickness and chord wise length of the deformable trailing edge section. Furthermore a wind turbine blade (1) is described, having at least one of such trailing edge section (s) (3) and to a system (11) for mounting a blade section (3) on a main blade (2) of a wind turbine. In addition a method of manufacturing a deformable trailing edge section (3) of a wind turbine blade (1) is disclosed.

Abstract: A deformable trailing edge section (3) of a wind turbine blade (1), at least part of said section (3) being formed in a deformable material. The blade section (3) comprises one or more cavities (5) being in connection with or connectable to a fluid source in a way that allows fluid to stream from the fluid source to the cavity or cavities (5), so that the shape of the deformable trailing edge section (3) and thereby the camber of the blade cross-section (3) is changeable by the pressure of fluid in the cavity or cavities (5) with insignificant changes of the thickness and chord wise length of the deformable trailing edge section. Furthermore a wind turbine blade (1) is described, having at least one of such trailing edge section (s) (3) and to a system (11) for mounting a blade section (3) on a main blade (2) of a wind turbine. In addition a method of manufacturing a deformable trailing edge section (3) of a wind turbine blade (1) is disclosed.